Laboratory and field evaluation of the pathogenicity of entomopathogenic nematodes to the red palm weevil, Rhynchophorus ferrugineus (Oliv.) (Col.: Curculionidae)

Ten Egyptian and imported entomopathogenic nematodes were evaluated for their pathogenicity to R. ferrugineus in both the laboratory and the field. In the laboratory, most nematodes were pathogenic to the pest larvae, pupae and adults. Larvae and adults were more susceptible to nematode infection (mostly 100% mortality) than pupae enclosed in their cocoons. In the field however, the highest insect larval mortality was 66.67% and most of nematodes failed in controlling the pest. Such failure could be due to hot weather, the tunnelling behaviour of the pest larvae and the too much sap in the infested sites in the trunks of palm trees.     

Surface Ultrastructure of Ultimobranchial Epithelium in the Thyroid Gland of Donkey (Equus asinus)

Surface ultrastructural observation of the thyroid gland in donkey revealed the coexistence of certain unusual follicles or cysts, the ultimobranchial (UB) follicles, which exhibited large diameters and less regular outlines. In addition, several small follicles, cell nests or solid cellular masses were also demonstrated in association with these structures. Surface of most UB follicular cells was almost hexagonal in shape, studded with sparse or dense pleomorphic microvilli, which were much denser at the cellular borders. Each follicular cell bore single cilium that projecting over the cell surface. Interestingly, bleb-like apocrine protrusion of the apical cytoplasm of some follicular cells was frequently demonstrated. These apocrine blebs (or aposomes) were varied in shape, size and showed smooth or irregular surface. In addition to such aposomes, deep to shallow circumscribed or eroded areas of the apical cell surface was frequently demonstrated. These findings indicate that the UB follicular cells in donkeys, similar to those of camels, exhibit an apocrine activity alongside with the usual merocrine mode of secretion.     

Comparison of blood serum proteins in water buffaloes with traumatic reticuloperitonitis and sequellae

In this study, 73 cows with different types of traumatic reticuloperitonitis (TRP) and sequellae along with 25 healthy buffalo cows were used to evaluate the total blood serum protein and protein electrophoresis. According to rumenotomy or necropsy findings, the affected buffalo cows were classified into acute local TRP (AL-TRP), chronic local TRP (CL-TRP), reticular abscess (RA), acute diffuse TRP (AD-TRP), purulent pericarditis (PPC) and fibrinous pericarditis (FPC). Polyclonal gammopathy was characteristic for the electrophoretogram of buffalo cows with CL-TRP (55%), RA (61.1%) and PPC (62.5%). Various degrees of hypoalbuminaemia, hyper-alpha-globulinaemia and low A/G ratios were the associated changes in all cases of TRP and sequellae. Hyper-beta-globulinaemia was noticed in cases with CL-TRP, RA and PPC. Hyper-gamma-globulinaemia was evident in cases with AL-TRP, CL-TRP, RA and PPC. Hyperproteinaemia was noticed in buffalo cows with local complications of TRP including AL-TRP, CL-TRP and RA. Hypoproteinaemia associated with severe hypoalbuminaemia (>50% reduction compared to controls) and very low A/G ratios (<0.4) characterized buffalo cows with AD-TRP, PPC or FPC. In conclusion, the concentrations and electrophoretic patterns of serum proteins in buffaloes differ according to the anatomical location of the foreign body and the associated pathological lesions.     

Modulatory effects of vitamin C on biochemical and oxidative changes induced by acute exposure to diazinon in rat various tissues: Prophylactic and therapeutic roles

Diazinon (DZN) as an organophosphate pesticide may cause oxidative stress in different tissues. Antioxidants increase tissue protection from oxidative stress. The aim of the present study was to investigate prophylactic and therapeutic effects of vitamin C against oxidative stress caused by DZN in various tissues of male Wistar rats. Thirty rats were divided into five groups: control group received corn oil as DZN solvent, DZN group received 100 mg/kg of DZN, C group received 200 mg/kg of vitamin C, C‐DZN and DZN‐C groups received vitamin C before and after DZN injection. Plasma and various tissues were prepared and evaluated for measurement of the biochemical parameters and oxidative stress biomarkers. Results showed that acute administration of DZN significantly increased superoxide dismutase and glutathione‐S‐transferase activities and malondialdehyde level in all tissues, catalase (CAT) activity in liver, kidney and heart and some plasma biochemical indices, while it decreased cholinesterase and lactate dehydrogenase activities and glutathione content in all tissues. CAT activity in erythrocytes, brain and spleen was decreased in DZN‐exposed rats compared with the control group. Administration of vitamins C in both prophylactic and therapeutic groups ameliorated in these parameters, although all these tests in tissues did not return to the normal level. These data suggest that oxidative stress is an essential mechanism involved in DZN‐induced adversity effect, as evidenced by the altered activity of antioxidant enzymes, depleted GSH content and the enhanced membrane lipid peroxidation. Both the prophylactic and therapeutic treatments of rats to vitamin C have beneficial effects against oxidative stress and cholinergic hyperactivity induced by DZN in tissues especially in the brain tissue through free radical scavenging.     

Intestinal gene expressions in broiler chickens infected with Escherichia coli and dietary supplemented with probiotic,acidifier and synbiotic

In this study, we investigated the effects of probiotic, acidifier and synbiotic supplementation on growth performance, mortality rate, intestinal gene expressions, fecal shedding, and organs colonization induced by Escherichia coli in broiler chickens. Six experimental groups were included; negative control group (NC), positive control group (PC), probiotic group (PR), acidifier group (AC), synbiotic group (SY) and colistin sulfate group (CS). Chickens in groups NC and PC were fed a basal diet, while chickens in groups PR, AC, SY, and CS were fed a basal diet containing probiotic, acidifier, synbiotic and colistin sulfate, respectively from the 1st day to the 28th day of age. At 7 days of age, all groups (not NC) were orally challenged with 0.5 ml (1.0?×?10⁹ CFU/ml) E. coli O78. The dietary supplementation of acidifier and synbiotic were sufficient to quell the devastating effects of E. coli infection in broilers. Growth performances represented by body weight gain, feed intake and feed conversion ratio were significantly improved as well as, mortalities were prevented whilst the ileal pro-inflammatory gene expressions (IL-6, IL-8, IL-13, TLR-4, IFN-γ, LITAF, AvBD-2, and AvBD-9) were significantly downregulated and the anti-inflammatory cytokine (IL-10) was significantly increased. In addition, E. coli fecal shedding and organs colonization was significantly diminished. It was concluded that the addition of both acidifier and synbiotic to the diet of broilers infected with E. coli could modulate the intestinal inflammatory responses induced by E. coli infection and minimized the inflammation-induced damage which resulted in improvement in growth performance, prevention of mortalities and reduction of E. coli environmental contamination.

     

Consequences of high temperature under changing climate optima for rice pollen characteristics-concepts and perspectives

The enhancement in both frequency and intensity of high temperature, besides its large variability will result in up to 40% yield reduction in rice by the end of 21^st century. Vegetative growth in rice continues with day time temperature up to 40°C but development of florets is extremely sensitive to temperature higher than 35°C. The effect of night time temperature stress is even more adverse than day. Heat stress results in deprived anther dehiscence, impaired pollination and abnormal pollen germination that cause floret sterility. The decrease in pollen viability is presumably caused by imbalance in proteins expression, abandoned biosynthesis, partitioning and translocation of soluble sugars, imbalance in phytohormones release, and loss of pollen water content. Rice responds to heat stress by adjusting various physiochemical mechanisms viz., growth inhibition, leaf senescence and alteration in basic physiological processes. Antioxidant enzymes, calcium and iron also play an important role in managing heat stress. Response of rice to heat stress varies with plant ecotype, growth stage, heat intensity and time of stress application. High temperature stress can be managed by developing heat-tolerant genotypes. Rice breeding and screening may be based on anther dehiscence, pollen tube development and pollen germination on stigma.     

Incidence of systemic granulomatosis is modulated by the feeding sequence and type of enrichment in meagre (Argyrosomus regius) larvae

Systemic granulomatosis is the most frequent disease in juvenile and adult meagre, but studies regarding the first appearance of granulomas in larvae do not exist. In order to evaluate this, meagre larvae were fed four different feeding regimes as follows: RS and RO (rotifer enriched with Easy DHA Selco or Ori‐Green from 3 to 30 dph respectively), RAS and RAO (rotifer enriched with Easy DHA Selco or Ori‐Green from 3 to 21 dph and Artemia enriched with Easy DHA Selco or Ori‐Green from 12 to 30 dph respectively). All treatments were also fed with commercial microdiet from 20 to 30 dph. At 30 dph weight, length, specific growth rate and survival were significantly higher in Artemia‐fed larvae, regardless of the enrichment. Microscopic first appearance of granulomas was observed in 20 dph larvae fed RS and RO. At 30 dph granulomas and thiobarbituric acid reactive substances (TBARS), values were significantly higher in RS and RO‐fed larvae than in RAS and RAO‐fed larvae. The results showed that granulomas first appeared in meagre larvae at 20 dph when fed rotifers only. Conversely, a reduced appearance of granulomas and lipid peroxidation occurs when Artemia is included in the feeding sequence reinforcing the hypothesis of a nutritional origin of the systemic granulomatosis.